2022-04-07 09:03:12

by Menglong Dong

Subject: [PATCH RESEND net-next v5 1/4] net: sock: introduce sock_queue_rcv_skb_reason()

From: Menglong Dong <[email protected]>

In order to report the reasons of skb drops in 'sock_queue_rcv_skb()',
introduce the function 'sock_queue_rcv_skb_reason()'.

As the return value of 'sock_queue_rcv_skb()' is used as the error code,
we can't make it as drop reason and have to pass extra output argument.
'sock_queue_rcv_skb()' is used in many places, so we can't change it
directly.

Introduce the new function 'sock_queue_rcv_skb_reason()' and make
'sock_queue_rcv_skb()' an inline call to it.

Reviewed-by: Hao Peng <[email protected]>
Reviewed-by: Jiang Biao <[email protected]>
Signed-off-by: Menglong Dong <[email protected]>
---
include/net/sock.h | 9 ++++++++-
net/core/sock.c | 30 ++++++++++++++++++++++++------
2 files changed, 32 insertions(+), 7 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index c4b91fc19b9c..1a988e605f09 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2392,7 +2392,14 @@ int __sk_queue_drop_skb(struct sock *sk, struct sk_buff_head *sk_queue,
void (*destructor)(struct sock *sk,
struct sk_buff *skb));
int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
-int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb);
+
+int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
+ enum skb_drop_reason *reason);
+
+static inline int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+{
+ return sock_queue_rcv_skb_reason(sk, skb, NULL);
+}

int sock_queue_err_skb(struct sock *sk, struct sk_buff *skb);
struct sk_buff *sock_dequeue_err_skb(struct sock *sk);
diff --git a/net/core/sock.c b/net/core/sock.c
index 1180a0cb0110..2cae991f817e 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -503,17 +503,35 @@ int __sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
}
EXPORT_SYMBOL(__sock_queue_rcv_skb);

-int sock_queue_rcv_skb(struct sock *sk, struct sk_buff *skb)
+int sock_queue_rcv_skb_reason(struct sock *sk, struct sk_buff *skb,
+ enum skb_drop_reason *reason)
{
+ enum skb_drop_reason drop_reason;
int err;

err = sk_filter(sk, skb);
- if (err)
- return err;
-
- return __sock_queue_rcv_skb(sk, skb);
+ if (err) {
+ drop_reason = SKB_DROP_REASON_SOCKET_FILTER;
+ goto out;
+ }
+ err = __sock_queue_rcv_skb(sk, skb);
+ switch (err) {
+ case -ENOMEM:
+ drop_reason = SKB_DROP_REASON_SOCKET_RCVBUFF;
+ break;
+ case -ENOBUFS:
+ drop_reason = SKB_DROP_REASON_PROTO_MEM;
+ break;
+ default:
+ drop_reason = SKB_NOT_DROPPED_YET;
+ break;
+ }
+out:
+ if (reason)
+ *reason = drop_reason;
+ return err;
}
-EXPORT_SYMBOL(sock_queue_rcv_skb);
+EXPORT_SYMBOL(sock_queue_rcv_skb_reason);

int __sk_receive_skb(struct sock *sk, struct sk_buff *skb,
const int nested, unsigned int trim_cap, bool refcounted)
--
2.35.1

2022-04-11 08:19:13

by David Ahern

Subject: Re: [PATCH RESEND net-next v5 1/4] net: sock: introduce sock_queue_rcv_skb_reason()

On 4/7/22 12:20 AM, [email protected] wrote:
> From: Menglong Dong <[email protected]>
>
> In order to report the reasons of skb drops in 'sock_queue_rcv_skb()',
> introduce the function 'sock_queue_rcv_skb_reason()'.
>
> As the return value of 'sock_queue_rcv_skb()' is used as the error code,
> we can't make it as drop reason and have to pass extra output argument.
> 'sock_queue_rcv_skb()' is used in many places, so we can't change it
> directly.
>
> Introduce the new function 'sock_queue_rcv_skb_reason()' and make
> 'sock_queue_rcv_skb()' an inline call to it.
>
> Reviewed-by: Hao Peng <[email protected]>
> Reviewed-by: Jiang Biao <[email protected]>
> Signed-off-by: Menglong Dong <[email protected]>
> ---
> include/net/sock.h | 9 ++++++++-
> net/core/sock.c | 30 ++++++++++++++++++++++++------
> 2 files changed, 32 insertions(+), 7 deletions(-)
>

Reviewed-by: David Ahern <[email protected]>